Phase-To-Earth Faults - ABB RET670 Installation And Commissioning Manual

Section 13
Verifying settings by secondary injection
13.5.3.2
126
jX
p3
ZPP
3
IEC07000009 V2 EN
Figure 56: Proposed test points for phase-to-phase fault
Label Description
ZPP1 The measured impedance for phase-to-phase fault at point 1 (zone reach ZPP) ohm/
phase.
ZAngPP The characteristic angel for phase-to-phase fault in degrees.
ZPP2 and ZPP3 The fault impedance for phase-to-phase fault at the boundary for the zone reach at
point 2 and 3.
Table 24: Test points for phase-to-phase
Test R
points
1 ZPP · cos(ZAngPP)
2 ZPP/2 + ΔR=ZPP/2 · (1 + cos(ZAngPP))
3 ZPP/2 - ΔR = ZPP/2 · (1-cos(ZAngPP))
Change the magnitude and angle of phase-to-phase voltage to achieve impedances
at test points p1, p2 and p3. For each test point, observe that the output signals,
START, STLx and STPP are activated where x refers to the actual phase to be
tested. After the timer tPP for the actual zone has elapsed, also the signals TRIP,
TRPP and TRx shall be activated.

Phase-to-earth faults

For simplicity, the same test points as for phase-to-phase faults are proposed, but
considering new impedance values.
p1
ZPP
1
p2
ZPP
2
AngPP
R
Ohm/phase
en07000009.vsd
X
ZPP · sin(ZAngPP)
ZPP/2 · sin(ZAngPP)
ZPP/ · sin(ZAngPP)
Installation and commissioning manual
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